Lyme disease is now the most common tick borne disease in the United States. Currently, disease prophylaxis has centered mainly on education programs and the personal use of acaricides and repellents on clothing. A number of other strategies have been suggested, many of them involving attempts to reduce tick population abundance. However, the effort is by no means straight forward. Strategies for the management of several tick borne diseases on man and domestic animals benefit from the insights of a considerable theoretical literature on the ecology of the tick species involved. A comparable literature for Ixodes dammini, the tick vector of Lyme borreliosis, does not yet exist and this hampers a priori evaluation of plausible control strategies. We propose to construct a mathematical model for the population biology of I. dammini. This model is the first and essential step in the construction of a useful model for the epizootiology of Lyme borreliosis to be used in the evaluation and development of disease control strategies. The modelling process is predicated upon the measurement of certain critical life-table parameters. We propose to measure the development and mortality of eggs, larvae, nymphs and unfed adults in the laboratory and in the field. We further propose to examine putative mechanisms for the regulation of tick population density. The formal structure of the model will be based on the outcome of the laboratory measures of stage development and survival. The first round of field studies will be used to amend that formal structure so that it more closely mimics events in the field. the second round of field studies will be used to text the adequacy of the model so derived.